Opto-electronic assembly

Abstract

An assembly of electronic components providing means for reception of data using an optical fibre wherein said assembly comprises: a photodiode; an amplifier coupled to said photodiode a printed circuit board, said photodiode and amplifier physically mounted on a first side of said printed circuit board; and a stiffener attached to said printed circuit board, wherein said stiffener is attached in a region approximately concentric with said region of said printed circuit board whereon said photodiode and amplifier are mounted, and conducting bond wires configured to directly couple said amplifier and said photodiode to conducting traces on a second opposite side of said printed circuit board with respect to said amplifier and said photodiode; and a fibre alignment ferrule and lens cap assembly, wherein said fibre alignment ferrule and lens cap assembly comprises: a ferrule which is configured to configured to provide a receptacle with defined physical alignment for an optical fibre; a lens which is configured to focus light from said optical fibre on to said photodiode; a cover region configured to provide an hermetic seal for said amplifier and said photodiode, wherein said fibre alignment ferrule and lens cap assembly is configured to be physically attached to said printed circuit board so as to provide an hermetic seal for said photodiode and amplifier and to further align said lens within said fibre alignment ferrule and lens cap assembly so as to focus light from said optical fibre onto said photodiode.

What is claimed is: 
     
         1 . An assembly of electronic components providing means for reception of data using an optical fibre wherein said assembly comprises:
 a photodiode;   an amplifier coupled to said photodiode   a flexible printed circuit board, said photodiode and amplifier physically mounted directly on a first side of said flexible printed circuit board; and   a stiffener attached to said flexible printed circuit board, wherein said stiffener is attached to a second side of said flexible printed circuit board opposite to said photodiode and amplifier, and wherein said stiffener is attached in a region approximately concentric with said region of said flexible printed circuit board whereon said photodiode and said amplifier are mounted, and   conducting bond wires configured to directly couple said amplifier and said photodiode to conducting traces on a second opposite side of said flexible printed circuit board with respect to said amplifier and said photodiode; and   a fibre alignment cover and lens cap assembly, wherein said fibre alignment cover and lens cap assembly comprises:
 a combined fibre alignment ferrule and lens cap component, configured to provide a receptacle with defined physical alignment for an optical fibre, and to further configured to provide a cover region configured to provide an hermetic seal for said amplifier and said photodiode, and which is further configured to hold a lens in an opening between the end of said fibre and said photodiode: 
 a lens which is configured to focus light from said optical fibre on to said photodiode; 
   wherein said combined fibre alignment ferrule and lens cap component is configured to be physically attached to said flexible printed circuit board so as to provide an hermetic seal for said photodiode and amplifier and to further align said lens within said fibre alignment ferrule and lens cap assembly so as to focus light from said optical fibre onto said photodiode.   
     
     
         2 . The assembly as claimed in  claim 1  wherein said assembly further comprises ancillary electronic components mounted on said flexible printed circuit board and covered by said combined fibre alignment ferrule and lens cap component. 
     
     
         3 . The assembly as claimed in  claim 2 , wherein an area of said first side of said flexible printed circuit board has a first region that substantially matches an outline of said contact region of a base of said combined fibre alignment ferrule and lens cap component and said first region of said flexible printed circuit board has applied thereto a layer of adhesive, wherein said adhesive permits adjustment of attached components until a curing process is performed. 
     
     
         4 . The assembly as claimed in  claim 3 , wherein said region whereon there is applied said adhesive is arranged in a concentric manner around a location of said photodiode. 
     
     
         5 . The assembly as claimed in  claim 4 , wherein said combined fibre alignment ferrule and lens cap component is attached to said first side of said first region of said flexible printed circuit board by said adhesive. 
     
     
         6 . The assembly as claimed in  claim 3  wherein holes are formed through said first region of said flexible printed circuit board of sufficient diameter to permit said adhesive to flow though said holes when said adhesive is applied to said first region. 
     
     
         7 . The assembly as claimed in  claim 6  wherein said first region of said flexible printed circuit board has applied thereto a layer of said adhesive, wherein said adhesive is sufficiently fluid to flow through said holes in said first region, and wherein said adhesive permits adjustment of attached components until a curing process is performed. 
     
     
         8 . The assembly as claimed in  claim 7  wherein said combined fibre alignment ferrule and lens cap component and said stiffener are attached to said flexible printed circuit board by said adhesive applied to said first region and wherein said adhesive has been made to flow through said holes in said first region. 
     
     
         9 . The assembly in  claim 5  wherein a final position of said combined fibre alignment ferrule and lens cap component is adjusted to provide satisfactory coupling of optical signals to said photodiode; and after said adjustment is completed said adhesive is subject to a curing process to fix said position of said combined fibre alignment ferrule and lens cap component. 
     
     
         10 . The assembly as claimed in  claim 1 , wherein a vent hole is provided to allow gas pressure differences between an inside of said combined fibre alignment ferrule and lens cap component and an external atmosphere to be released. 
     
     
         11 . A method of assembly of electronic components to provide means for reception of data using an optical fibre, said method comprising:
 providing a flexible printed circuit board, wherein said flexible printed circuit board is configured to have conducting traces in defined regions;   physically mounting directly on a first side of said flexible printed circuit board a photodiode and an amplifier;   providing a stiffener attached to said flexible printed circuit board, wherein said stiffener is attached to a second side of said flexible printed circuit board opposite to said photodiode and said amplifier and wherein said stiffener is attached in a region approximately concentric with said region of said printed circuit board upon which said photodiode and said amplifier are mounted;   providing on said flexible printed circuit board holes through said board configured to provide means of electrical connection between opposite sides of said flexible printed circuit board;   providing a combined fibre alignment ferrule and lens cap component, wherein said combined fibre alignment ferrule and lens cap component comprises:
 a combined fibre alignment ferrule and lens cap component, configured to provide a receptacle with defined physical alignment for an optical fibre, and to further configured to provide a cover region configured to provide an hermetic seal for said amplifier and said photodiode, and which is further configured to hold a lens in an opening between the end of said fibre and said photodiode a lens which is configured to focus light from said optical fibre on to said photodiode; 
   physically attaching said combined fibre alignment ferrule and lens cap component to said flexible printed circuit board so as to provide an hermetic seal for said photodiode and amplifier;   aligning a position of said combined fibre alignment ferrule and lens cap component such that said lens within said combined fibre alignment ferrule and lens cap component is able to focus light from said optical fibre onto said photodiode.   
     
     
         12 . A method of assembly of electronic components as claimed in  claim 11  wherein said combined fibre alignment ferrule and lens cap component is configured to cover said photodiode and said amplifier on said flexible printed circuit board. 
     
     
         13 . A method of assembly of electronic components as claimed in  claim 12 , wherein said combined fibre alignment ferrule and lens cap component is attached to said flexible printed circuit board using an adhesive, wherein said adhesive is configured to permit adjustment of said position of said fibre alignment ferrule and lens cap assembly before curing of said adhesive. 
     
     
         14 . A method of assembly of electronic components as claimed in  claim 11 , wherein at least one said hole is provided within a region of said flexible printed circuit board covered by said combined fibre alignment ferrule and lens cap component. 
     
     
         15 . A method of assembly of electronic components as claimed in  claim 14  wherein connections between said conductive traces on said flexible printed circuit board and said photodiode are made via said at least one hole provided within said region of said flexible printed circuit board.